Philippines: Tropical Storm 1 tracking northwestward over Calabarzon Region early May 26 /update 2

Tropical Storm 1 (known locally in the Philippines as Aghon) is tracking northwestward across Quezon Province, Calabarzon Region, early May 26, following landfalls over Homonhon Island late May 24 and near Giporlos Municipality in Eastern Samar Province early May 25, Masbate Island in Bicol Region May 25, and Marinduque Province in Mimaropa Region late May 25, as well as Quezon Province, Calabarzon Region, early May 26. As of 05:00 PHST, the storm's center of circulation was approximately 125 km (77 miles) southeast of Manila.

Forecast models indicate that the system will strengthen into a severe tropical storm as it tracks north-northwestward over Quezon Province in the Calabarzon Region, making landfalls over the eastern parts of the province through the afternoon of May 26, before turning to track northeastward and moving out into the Philippine Sea. Once over open water, the system is expected to strengthen further as it continues to track northeastward off the east coast of Luzon through May 27. The storm will strengthen briefly into a typhoon early May 28-29 before weakening back to a severe tropical storm as it continues to track northeastward over the northwestern Philippine Sea through early May 31. The storm's track and intensity forecast remains somewhat uncertain, and changes may occur over the coming hours and days.

The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) has warned of continued heavy rainfall across parts of the central and northern Philippines; rainfall accumulations of more than 20 cm (8 inches) are forecast over Quezon Province in the Calabarzon Region and rainfall accumulations of 10-20 cm (4-8 inches) are likely over Aurora, eastern Bulacan, Rizal, Laguna, Metro Manila, and Camarines Norte provinces through the evening of May 27. Lesser rainfall is forecast over the rest of northern and central Philippines. Tropical Cyclone Wind Signal 2 is in place across Calabarzon Region, and Tropical Cyclone Wind Signal 1 over the rest of northern and central Philippines. Extreme general flood advisories (second highest level on a five-tier scale) are in place across the Bicol Region.

Several domestic flights connecting Manila with Calbayog, Naga, Romblon, Siargao, Surigao, Tacloban, and Virac have been canceled May 25 and San Jose, Naga, and Virac May 26 due to the adverse weather; further flight disruptions are possible over the coming hours. The Philippine Ports Authority (PPA) has advised against non-essential maritime travel during the storm. The Philippine Coast Guard (PCG) suspended sea travel for all vessels in Quezon, Marinduque, and Romblon provinces. Several ferry services have been suspended, including those connecting Masbate City with Albay, Cebu, and Samar provinces have been canceled. As of early May 26, more than 3,600 passengers in Eastern Visayas Region, 1,400 in Bicol Region, and 1,300 in Calabarzon Region were stranded at ports due to the adverse weather. Authorities have warned that more than 1,100 villages from 52 cities and municipalities in Bicol Region are under moderate to very high threats of landslides. Local officials have evacuated an unconfirmed number of residents from high-risk areas in the Pasacao area due to the risk of flooding, landslides, and storm surges.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. Localized evacuations, flash flooding, and landslides are possible.

The inclement weather could trigger localized business, transport, and utility disruptions, rendering some bridges or roadways impassable. Flight disruptions at regional airports and temporary closures of ports are also possible. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Raw sewage and other hazardous materials mixed with floodwaters pose a serious health threat.